* Escape 124 Video Decoder
* Copyright (C) 2008 Eli Friedman (eli.friedman@gmail.com)
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#define BITSTREAM_READER_LE
#include "avcodec.h"
-
-#define ALT_BITSTREAM_READER_LE
#include "bitstream.h"
+#include "internal.h"
typedef union MacroBlock {
uint16_t pixels[4];
typedef struct CodeBook {
unsigned depth;
unsigned size;
- MacroBlock blocks[0];
+ MacroBlock* blocks;
} CodeBook;
typedef struct Escape124Context {
- AVFrame frame;
+ AVFrame *frame;
unsigned num_superblocks;
- CodeBook* codebooks[3];
+ CodeBook codebooks[3];
} Escape124Context;
-static int can_safely_read(GetBitContext* gb, int bits) {
- return get_bits_count(gb) + bits <= gb->size_in_bits;
+static int can_safely_read(BitstreamContext *bc, int bits)
+{
+ return bitstream_bits_left(bc) >= bits;
}
/**
{
Escape124Context *s = avctx->priv_data;
- avctx->pix_fmt = PIX_FMT_RGB555;
+ avctx->pix_fmt = AV_PIX_FMT_RGB555;
s->num_superblocks = ((unsigned)avctx->width / 8) *
((unsigned)avctx->height / 8);
+ s->frame = av_frame_alloc();
+ if (!s->frame)
+ return AVERROR(ENOMEM);
+
return 0;
}
Escape124Context *s = avctx->priv_data;
for (i = 0; i < 3; i++)
- av_free(s->codebooks[i]);
+ av_free(s->codebooks[i].blocks);
- if (s->frame.data[0])
- avctx->release_buffer(avctx, &s->frame);
+ av_frame_free(&s->frame);
return 0;
}
-static CodeBook* unpack_codebook(GetBitContext* gb, unsigned depth,
+static CodeBook unpack_codebook(BitstreamContext *bc, unsigned depth,
unsigned size)
{
unsigned i, j;
- CodeBook* cb;
+ CodeBook cb = { 0 };
- if (!can_safely_read(gb, size * 34))
- return NULL;
+ if (!can_safely_read(bc, size * 34))
+ return cb;
- if (size >= (INT_MAX - sizeof(CodeBook)) / sizeof(MacroBlock))
- return NULL;
- cb = av_malloc(size * sizeof(MacroBlock) + sizeof(CodeBook));
- if (!cb)
- return NULL;
+ if (size >= INT_MAX / sizeof(MacroBlock))
+ return cb;
+ cb.blocks = av_malloc(size ? size * sizeof(MacroBlock) : 1);
+ if (!cb.blocks)
+ return cb;
- cb->depth = depth;
- cb->size = size;
+ cb.depth = depth;
+ cb.size = size;
for (i = 0; i < size; i++) {
- unsigned mask_bits = get_bits(gb, 4);
- unsigned color0 = get_bits(gb, 15);
- unsigned color1 = get_bits(gb, 15);
+ unsigned mask_bits = bitstream_read(bc, 4);
+ unsigned color0 = bitstream_read(bc, 15);
+ unsigned color1 = bitstream_read(bc, 15);
for (j = 0; j < 4; j++) {
if (mask_bits & (1 << j))
- cb->blocks[i].pixels[j] = color1;
+ cb.blocks[i].pixels[j] = color1;
else
- cb->blocks[i].pixels[j] = color0;
+ cb.blocks[i].pixels[j] = color0;
}
}
return cb;
}
-static unsigned decode_skip_count(GetBitContext* gb)
+static unsigned decode_skip_count(BitstreamContext *bc)
{
unsigned value;
// This function reads a maximum of 23 bits,
// which is within the padding space
- if (!can_safely_read(gb, 1))
+ if (!can_safely_read(bc, 1))
return -1;
- value = get_bits1(gb);
+ value = bitstream_read_bit(bc);
if (!value)
return value;
- value += get_bits(gb, 3);
+ value += bitstream_read(bc, 3);
if (value != (1 + ((1 << 3) - 1)))
return value;
- value += get_bits(gb, 7);
+ value += bitstream_read(bc, 7);
if (value != (1 + ((1 << 3) - 1)) + ((1 << 7) - 1))
return value;
- return value + get_bits(gb, 12);
+ return value + bitstream_read(bc, 12);
}
-static MacroBlock decode_macroblock(Escape124Context* s, GetBitContext* gb,
- int* codebook_index, int superblock_index)
+static MacroBlock decode_macroblock(Escape124Context *s, BitstreamContext *bc,
+ int *codebook_index, int superblock_index)
{
// This function reads a maximum of 22 bits; the callers
// guard this function appropriately
unsigned block_index, depth;
-
- if (get_bits1(gb)) {
+ int value = bitstream_read_bit(bc);
+ if (value) {
static const char transitions[3][2] = { {2, 1}, {0, 2}, {1, 0} };
- *codebook_index = transitions[*codebook_index][get_bits1(gb)];
+ value = bitstream_read_bit(bc);
+ *codebook_index = transitions[*codebook_index][value];
}
- depth = s->codebooks[*codebook_index]->depth;
-
- // depth = 0 means that this shouldn't read any bits;
- // in theory, this is the same as get_bits(gb, 0), but
- // that doesn't actually work.
- block_index = depth ? get_bits(gb, depth) : 0;
+ depth = s->codebooks[*codebook_index].depth;
+ block_index = bitstream_read(bc, depth);
if (*codebook_index == 1) {
- block_index += superblock_index << s->codebooks[1]->depth;
+ block_index += superblock_index << s->codebooks[1].depth;
}
// This condition can occur with invalid bitstreams and
// *codebook_index == 2
- if (block_index >= s->codebooks[*codebook_index]->size)
+ if (block_index >= s->codebooks[*codebook_index].size)
return (MacroBlock) { { 0 } };
- return s->codebooks[*codebook_index]->blocks[block_index];
+ return s->codebooks[*codebook_index].blocks[block_index];
}
static void insert_mb_into_sb(SuperBlock* sb, MacroBlock mb, unsigned index) {
0x100, 0x200, 0x1000, 0x2000,
0x400, 0x800, 0x4000, 0x8000};
-/**
- * Decode a single frame
- * @param avctx decoder context
- * @param data decoded frame
- * @param data_size size of the decoded frame
- * @param buf input buffer
- * @param buf_size input buffer size
- * @return 0 success, -1 on error
- */
static int escape124_decode_frame(AVCodecContext *avctx,
- void *data, int *data_size,
- const uint8_t *buf, int buf_size)
+ void *data, int *got_frame,
+ AVPacket *avpkt)
{
+ const uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
Escape124Context *s = avctx->priv_data;
+ AVFrame *frame = data;
- GetBitContext gb;
+ BitstreamContext bc;
unsigned frame_flags, frame_size;
unsigned i;
uint16_t* old_frame_data, *new_frame_data;
unsigned old_stride, new_stride;
+ int ret;
- AVFrame new_frame = { { 0 } };
-
- init_get_bits(&gb, buf, buf_size * 8);
+ bitstream_init8(&bc, buf, buf_size);
// This call also guards the potential depth reads for the
// codebook unpacking.
- if (!can_safely_read(&gb, 64))
+ if (!can_safely_read(&bc, 64))
return -1;
- frame_flags = get_bits_long(&gb, 32);
- frame_size = get_bits_long(&gb, 32);
+ frame_flags = bitstream_read(&bc, 32);
+ frame_size = bitstream_read(&bc, 32);
// Leave last frame unchanged
// FIXME: Is this necessary? I haven't seen it in any real samples
if (!(frame_flags & 0x114) || !(frame_flags & 0x7800000)) {
+ if (!s->frame->data[0])
+ return AVERROR_INVALIDDATA;
+
av_log(NULL, AV_LOG_DEBUG, "Skipping frame\n");
- *data_size = sizeof(AVFrame);
- *(AVFrame*)data = s->frame;
+ *got_frame = 1;
+ if ((ret = av_frame_ref(frame, s->frame)) < 0)
+ return ret;
return frame_size;
}
if (i == 2) {
// This codebook can be cut off at places other than
// powers of 2, leaving some of the entries undefined.
- cb_size = get_bits_long(&gb, 20);
+ cb_size = bitstream_read(&bc, 20);
cb_depth = av_log2(cb_size - 1) + 1;
} else {
- cb_depth = get_bits(&gb, 4);
+ cb_depth = bitstream_read(&bc, 4);
if (i == 0) {
// This is the most basic codebook: pow(2,depth) entries
// for a depth-length key
cb_size = s->num_superblocks << cb_depth;
}
}
- av_free(s->codebooks[i]);
- s->codebooks[i] = unpack_codebook(&gb, cb_depth, cb_size);
- if (!s->codebooks[i])
+ av_free(s->codebooks[i].blocks);
+ s->codebooks[i] = unpack_codebook(&bc, cb_depth, cb_size);
+ if (!s->codebooks[i].blocks)
return -1;
}
}
- new_frame.reference = 3;
- if (avctx->get_buffer(avctx, &new_frame)) {
+ if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
- return -1;
+ return ret;
}
- new_frame_data = (uint16_t*)new_frame.data[0];
- new_stride = new_frame.linesize[0] / 2;
- old_frame_data = (uint16_t*)s->frame.data[0];
- old_stride = s->frame.linesize[0] / 2;
+ new_frame_data = (uint16_t*)frame->data[0];
+ new_stride = frame->linesize[0] / 2;
+ old_frame_data = (uint16_t*)s->frame->data[0];
+ old_stride = s->frame->linesize[0] / 2;
for (superblock_index = 0; superblock_index < s->num_superblocks;
superblock_index++) {
if (skip == -1) {
// Note that this call will make us skip the rest of the blocks
// if the frame prematurely ends
- skip = decode_skip_count(&gb);
+ skip = decode_skip_count(&bc);
}
if (skip) {
copy_superblock(sb.pixels, 8,
old_frame_data, old_stride);
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
+ while (can_safely_read(&bc, 1) && !bitstream_read_bit(&bc)) {
unsigned mask;
- mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
- mask = get_bits(&gb, 16);
+ mb = decode_macroblock(s, &bc, &cb_index, superblock_index);
+ mask = bitstream_read(&bc, 16);
multi_mask |= mask;
for (i = 0; i < 16; i++) {
if (mask & mask_matrix[i]) {
}
}
- if (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
- unsigned inv_mask = get_bits(&gb, 4);
+ if (can_safely_read(&bc, 1) && !bitstream_read_bit(&bc)) {
+ unsigned inv_mask = bitstream_read(&bc, 4);
for (i = 0; i < 4; i++) {
if (inv_mask & (1 << i)) {
multi_mask ^= 0xF << i*4;
} else {
- multi_mask ^= get_bits(&gb, 4) << i*4;
+ multi_mask ^= bitstream_read(&bc, 4) << i * 4;
}
}
for (i = 0; i < 16; i++) {
if (multi_mask & mask_matrix[i]) {
- if (!can_safely_read(&gb, 1))
+ if (!can_safely_read(&bc, 1))
break;
- mb = decode_macroblock(s, &gb, &cb_index,
+ mb = decode_macroblock(s, &bc, &cb_index,
superblock_index);
insert_mb_into_sb(&sb, mb, i);
}
}
} else if (frame_flags & (1 << 16)) {
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
- mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
- insert_mb_into_sb(&sb, mb, get_bits(&gb, 4));
+ while (can_safely_read(&bc, 1) && !bitstream_read_bit(&bc)) {
+ mb = decode_macroblock(s, &bc, &cb_index, superblock_index);
+ insert_mb_into_sb(&sb, mb, bitstream_read(&bc, 4));
}
}
av_log(NULL, AV_LOG_DEBUG,
"Escape sizes: %i, %i, %i\n",
- frame_size, buf_size, get_bits_count(&gb) / 8);
+ frame_size, buf_size, bitstream_tell(&bc) / 8);
- if (s->frame.data[0])
- avctx->release_buffer(avctx, &s->frame);
+ av_frame_unref(s->frame);
+ if ((ret = av_frame_ref(s->frame, frame)) < 0)
+ return ret;
- *(AVFrame*)data = s->frame = new_frame;
- *data_size = sizeof(AVFrame);
+ *got_frame = 1;
return frame_size;
}
-AVCodec escape124_decoder = {
- "escape124",
- CODEC_TYPE_VIDEO,
- CODEC_ID_ESCAPE124,
- sizeof(Escape124Context),
- escape124_decode_init,
- NULL,
- escape124_decode_close,
- escape124_decode_frame,
- CODEC_CAP_DR1,
+AVCodec ff_escape124_decoder = {
+ .name = "escape124",
+ .long_name = NULL_IF_CONFIG_SMALL("Escape 124"),
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_ESCAPE124,
+ .priv_data_size = sizeof(Escape124Context),
+ .init = escape124_decode_init,
+ .close = escape124_decode_close,
+ .decode = escape124_decode_frame,
+ .capabilities = AV_CODEC_CAP_DR1,
};
-
projects / ffmpeg / blobdiff